My iMac is a 2.5 GHz Intel Core i5
with 4 GB 1333 MHz DDR3
running OS X 10.9.5 (13F1911)
I have read that I should be able to upgrade to at least 10.13.
When I go to do a Software update, it says there are no updates available. What should I do?
iMac Pro
I'd add more RAM for certain, and don't use Firefox for this link...
https://itunes.apple.com/app/macos-high-sierra/id1246284741?mt=12
Our iMac of the same model (and same processor) is running quite well on 8GB RAM and High Sierra (macOS 10.13). The extra RAM is from OWC, one of the vendors padams35 wisely suggests. Ram installation is an easy at-home job and takes minutes. When we upgrade ours (the wife's computer), I had our grandson do it. He was 10 year old at the time.
Good RAM install video for that model here:
https://eshop.macsales.com/installvideos/imac_mid_2011_mem/iMac12-1/
I'd also suggest installing more memory (RAM). While it should run 10.13 with just 4GB it will run noticeably better with 8GB or 12GB. OWC (macsales) and Crucial both have high ratings and mac lookup tools to point you to the correct RAM.
how to update my 2011 mac
